摘要：SummaryOctopamine is essential for egg-laying inDrosophila melanogaster, but the neuronal pathways and receptors by which it regulates visceral muscles in the reproductive tract are not known. We find that the two octopamine receptors that have been previously implicated in egg-laying–OAMBandOctβ2R-are expressed in octopaminergic and glutamatergic neurons that project to the reproductive tract, peripheral ppk(+) neurons within the reproductive tract and epithelial cells that line the lumen of the oviducts. Further optogenetic and mutational analyses indicate that octopamine regulates both oviduct contraction and relaxation viaOctβ2andOAMBrespectively. Interactions with glutamatergic pathways modify the effects of octopamine. Octopaminergic activation of Octβ2R on glutamatergic processes provides a possible mechanism by which octopamine initiates lateral oviduct contractions. We speculate that aminergic pathways in the oviposition circuit may be comparable to some of the mechanisms that regulate visceral muscle contractility in mammals.Graphical abstractDisplay OmittedHighlights•The receptors Octβ2 and OAMB mediate oviduct muscle contraction and relaxation•The receptors are detectably expressed in neurons and epithelia but not muscle cells•The control of visceral muscles in flies and mammals may share common featuresMolecular physiology; Neuroscience; Cell biology
